Paper box and method of making the same



June 23, 1936.

C. L. CLAFF PAPER BOX AND METHOD OF-MAKING THE SAME Filed June 15, 1935 2 Sheets-Sheet 1 h w WWflfifihWll /l CL. CZdff June 23, C CLAFF 2,044,935

PAPER BOX AND METHOD OF MAKING THE SAME Filed June 13, 1935 Z'Sheets-Sheet 2 Patented June 23, 1936 UNITED STATES PATENT OFFICE PAPER BOX AND METHOD OF MAKING THE SAME Clarence Lloyd Claff, Randolph, Mass. Application June 13, 1935, Serial No. 26,479

-1 Claim.

This invention relates to paper boxes of the type commonly made of box ing of finishing paper producing the same.

board and an outer coverand also to a method of sented an objectionable appearance.

Various methods have been devised for overcoming this objection but all of them have been unsatisfac tory both because of the added material necessary in the construction of the box and the complicated machinery required to avoid the unsightly appearance of the corners due to the exposure of the raw edges.

It is an object of the present invention to provide a box which is rendered more attractive by the substantial elimination of the raw edges and without requiring the use of expensive mechanisms or added materials.

It is a further objec t of the invention to improve upon the construction of a box of the type shown, for example, in my co-pending application No. 755,601, filed on December 1, 1934, wherein the end walls of the box are produced by placing folded end flaps astride inturned end wings on the side walls, thus leaving at least one thickness of each folded end flap with its raw edges exposed.

described and pointed out in the claim, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

In the accompanyin forms of the invention In said drawings g drawings the preferred have been shown.

Figure 1 is a perspective view of one end portion of a box embodying the present improvements.

Figure 2 is an enlarged section on line 2--2 Figure 1.

Figure 3 is a plan view of one corner portion of a blank from which the box is formed.

Figure 4 is an enlarged section on line 44 of the blank at the time the same is being slitted in accordance with the present method.

Figure 5 is a horizon tal section on an enlarged scale through one corner portion of the box before it has been subjected to final compression.

Figure 6 is a view similar to Figure 5 showing the folded end portions after they have been compressed during the completion of the box. 5

Figure 7 is a plan view of a blank used in the formation of a slightly modified form of box.

Figure 8 is a perspective view of a portion of a box produced from said blank.

Figure 9 is an enlarged section on line 9-9 Fig- 10 ure 8.

Figure 10 is an enlarged section on line Ill-40 Figure 8.

Referring to the figures by characters of reference, I designates a blank formed of card board known to the trade as bulked up board which is of a loosely knitted body of required caliber. The edges of this board are preferably provided with kraft tape for reinforcing them and this tape, which extends longitudinally of the blank, can be applied at any time before the cutting and shaping of the blank. In the drawings the kraft tape has been indicated by dotted lines at 2. One surface of the blank is coated with finishing paper indicated generally at 3. After the web of material comprising board I, krait tape 2 and finishing paper 3 has been cut transversely to form a blank of proper length and has been scored longitudinally and transversely as at 4 to define the bottom portion 5, the side walls 6, and flaps l and side wings 8, the ends of this blank are slitted longitudinally as at 9 by special means for the purpose of eliminating raw edges. To accomplish this result the material of the blank is subjected to the action of a cutting tool In which can be rotatable or slidable to meet required conditions and the active edge of which can be so shaped that when forced into the material of the blank, as indicated in Figure 4, it will pinch through the finishing paper 3 and at the same time pinch through the box board I, this action serving to draw the edges of the finishing paper around the adjacent edge portions of the box board material as shown in Figure 4, thus to form a sharp or feather edge.

It is of course necessary to provide some resisting means such as a roller l, plate or other type of platen for cooperation with the edge of the tool l0 during the slitting operation.

After the materials have been treated as described the blank is folded by inturning the wings 8 and then folding the end flap 1 so that it will straddle these inturned wings 8. This will leave exposed at the outer surfaces of the corners only those edges which have been produced by slitting the material as heretofore described. Following 5 the folding operation the cooperating parts of the blank will be assembled at each corner substantially in the manner shown in Figure 5 at which time the offset edge portion I2 of the finishing paper will almost completely lap the raw edge of the box board. The lapping portions of the blank which are of course provided with glue in the usual manner are then compressed between forms or dies A and B and this compression will result in compacting the fibers of the lapping portions of the bulked up board, the overall thickness of the end wall thus being reduced substantially to the same caliber as that of the bottom portion of the box which has not been subjected to compression.

During the compressing action the olfset portions l2 of the finishing paper will be compressed back so as practically to conceal the raw edges of the box board, as shown in Figure 6, with the result that the completed box will be provided with well finished edges at the corners, and, although of a cheap construction requiring no more material than other cheap structures, will have a finish equally as presentable as that of other boxes more expensive to construct.

As a modification of the invention there has been illustrated in Figures 7 to 10 inclusive a structure which does not require the use of oifsets of the finishing material but practically the same results can be obtained by skiving the box board material. In this modified structure the blank I 3 is shaped to provide foldable end flaps M which are separated by slits l5 from Wings [6 extending from the side walls ll. Before the blank is folded to produce a box a portion of which has been shown in Figure 8, the sides of the end flaps I4 are reduced in thickness by skiving, as indicated at l8, so as to be brought to feather edges.

The blank is thereafter folded with its wings l6 extended toward each other after which the end flaps M are placed astride these inturned wings and then the lapping portions are subjected to pressure for the purpose of compacting them.

The outer surfaces of the flaps M which are coated with finishing paper l9, as is customary, will be pressed inwardly so that the finishing paper, as shown in Figure 9, will completely conceal the skived side portions of the folded flaps I 4, thereby producing a box the outer surfaces of which are free from any raw edges of the box board material, only the edges of the finishing paper being exposed. It is to be understood of course that in this type of box kraft tape can be used in the same manner as heretofore explained.

The term box heretofore used and also used in the appended claim is o be understood as of sufificient scope to apply to either the body or the lid portion of the box.

What is claimed is:

The method of forming a paper box which includes the step of shaping a blank made up of a thickness of paper board having one surface coated with finishing paper, pinching the blank to slit it and provide side wings and foldable end flaps and to also partly compress the material at the sides'of the slit so as to draw the finishing paper a sufiicient distance to partly conceal the raw edges of the end folds, thereafter folding the blank to position the end flaps astride the side wings, and subsequently subjecting the wings and the folded end flaps to final overall compression to reduce the overall thickness thereof and move the ofiset portions of the finishing paper into positions to substantially conceal the adjacent edges of the paper board.

CLARENCE LLOYD CLAFF. 

